Explaining how people reason is central to understanding ourselves as human beings. Complex deliberations that take unexpected turns are central to many good detective stories, but they are also ubiquitous in everyday life and academic research. While philosophers have studied both ends of complex deliberations-learning new information and reaching justified conclusions-little has been said about our states of mind when we are in the middle of thought. Yet, this stage of intellectual limbo is where we often produce genuine insight. Unfinished Business advances a new theory of the transitional stages of complex deliberation, integrating theoretical research in philosophy with empirical results from cognitive science. It postulates a new attitude type, transitional attitudes, that we hold towards potential answers to the question at hand while we're deliberating. Transitional attitudes possess their own rationality conditions that differ from the norms of rationality typically applied to conclusions of reasoning. The resulting abstract framework reveals deep structural similarities among such varied intellectual pursuits as determining the significance of a historical artefact, deciding on a person's guilt in court, deliberating about a philosophical problem, or searching for a mathematical proof. It can help us make progress on difficult philosophical questions, such as how we should respond to misleading higher-order evidence, how we should formally model logical learning, and how confident we can rationally be in our own philosophical positions.In this book, Julia Staffel makes a novel contribution to the study of reasoning and rationality. Most of the theorizing in these areas either studies the nature of simple inferences, or the conditions under which we can reach justified conclusions. Unfinished Business examines how we should theorize about the attitudes we have towards possible answers to a question of interest while our reasoning is ongoing. It focuses on complex reasoning processes that don't necessarily progress towards an answer in a linear way. Based on both philosophical arguments and empirical research, Staffel argues that there is a previously unrecognized attitude type, transitional attitudes, that play a key role in carrying out complex deliberations.